JPH02295222A - Discriminating device for proximity switch - Google Patents
Discriminating device for proximity switchInfo
- Publication number
- JPH02295222A JPH02295222A JP11681589A JP11681589A JPH02295222A JP H02295222 A JPH02295222 A JP H02295222A JP 11681589 A JP11681589 A JP 11681589A JP 11681589 A JP11681589 A JP 11681589A JP H02295222 A JPH02295222 A JP H02295222A
- Authority
- JP
- Japan
- Prior art keywords
- metal
- proximity switch
- value
- detected
- count value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000002184 metal Substances 0.000 claims abstract description 44
- 230000004907 flux Effects 0.000 claims abstract description 9
- 239000003990 capacitor Substances 0.000 claims description 8
- 230000002238 attenuated effect Effects 0.000 claims description 2
- 238000001514 detection method Methods 0.000 abstract description 9
- NLINVDHEDVEOMJ-UHFFFAOYSA-N 1-Methylamino-1-(3,4-Methylenedioxyphenyl)Propane Chemical compound CCC(NC)C1=CC=C2OCOC2=C1 NLINVDHEDVEOMJ-UHFFFAOYSA-N 0.000 abstract 3
- 102400000233 M-alpha Human genes 0.000 abstract 3
- 101800001695 M-alpha Proteins 0.000 abstract 3
- 238000010586 diagram Methods 0.000 description 7
- 238000013459 approach Methods 0.000 description 6
- 102100030551 Protein MEMO1 Human genes 0.000 description 1
- 101710176845 Protein MEMO1 Proteins 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
Landscapes
- Electronic Switches (AREA)
Abstract
Description
本発明はコイルとコンデンサとで減衰共振回路を構成す
る前記コイルの発生磁束内で被検出金属がコイルに近づ
いたか否かを前記共振の減衰の速さで判別する近接スイ
ッチにおける判別装置、特にスイッチ構成部品のバラッ
キに関わらず、スイッチの検出精度を高め得るようにし
た近接スイッチの判別装置に関する。
なお以下各図において同一の符号は同一もしくは相当部
分を示す。The present invention relates to a discrimination device for a proximity switch, which discriminates whether or not a metal to be detected approaches the coil within the magnetic flux generated by the coil, which constitutes a damped resonant circuit by a coil and a capacitor, based on the speed at which the resonance decays. The present invention relates to a proximity switch discrimination device that can improve switch detection accuracy regardless of variations in component parts. Note that in the following figures, the same reference numerals indicate the same or corresponding parts.
第2図はこの種の近接スイッチ(装置)の構成例を示す
回路図、第3図は第2図の動作説明用の波形図である。
第2図においてLはその発生磁束内で被検出金属が自身
へ接近したか否かを判別するコイル、Cはこのコイルし
に並列に接続されて共振回路を構成するコンデンサ、R
1はコイルLの通電電流制限用の抵抗、S1はパルス計
数制御回路2を介して駆動されコイルLの電流を開閉す
るトランジスタである。またR2,R3は直流定電圧電
源■CCから基準電圧VFを得るための分圧抵抗、3は
前記共振回路の電圧(この例では抵抗Rlとトランジス
タS1との接続点Pの電圧)と基準電圧VFとを比較す
る比較回路である。
2はトランジスタS1の開閉やパルス計数等を行うパル
ス計数制御回路、11はこの回路2に属するカウンタで
比較回路3の出力3aを計数する。
いまトランジスタS工を所定時間ONLてコイルLにほ
ぼ直流電圧VCCと抵抗R1とで定まる所定の電流を確
立させた状態でトランジスタS1をOFFすると、P点
の電位は第3図(1)のように電位vCCを中心として
その上下に振動する減衰振動波形となる。
そしてこのP点電位と基準電圧VFとを比較回路3を介
して比較した得た比較回路出力3aは第3図(2)のよ
うになる。
なお第3図(1), (2)において左側の波形は金属
無、即ちコイルLへの被検出金属の接近が無い場合を示
し、同じく右側の波形は金属有、即ちコイルLへの被検
出金属の接近が有る場合を示す。このように被検出金属
の接近によって共振波形の減衰が速く (強く)なる。
これはコイルLの発生する磁束の変化によってコイルし
に接近した被検出金属内に過電流が流れるためである。
このようにして比較回路出力3aとしてのパルス出力を
カウンタ11を介して計数するとこの計数値は被検出金
属の非接近時より接近時の方が小になる。
そこで従来は、第1図の計数N判別手段12を介しカウ
ンタ11の計数出力(パルス数)Aを1つのしきい値(
N)と比較し、パルス数AがN以上なら金属無、N未満
なら金属有と判定していた。FIG. 2 is a circuit diagram showing a configuration example of this type of proximity switch (device), and FIG. 3 is a waveform diagram for explaining the operation of FIG. In Figure 2, L is a coil that determines whether a metal to be detected approaches itself within the generated magnetic flux, C is a capacitor connected in parallel to this coil to form a resonant circuit, and R
1 is a resistor for limiting the current flowing through the coil L, and S1 is a transistor driven via the pulse counting control circuit 2 to open and close the current of the coil L. Further, R2 and R3 are voltage dividing resistors for obtaining the reference voltage VF from the DC constant voltage power supply CC, and 3 is the voltage of the resonant circuit (in this example, the voltage at the connection point P between the resistor Rl and the transistor S1) and the reference voltage. This is a comparison circuit that compares VF. 2 is a pulse counting control circuit for opening/closing the transistor S1 and counting pulses, and 11 is a counter belonging to this circuit 2, which counts the output 3a of the comparison circuit 3. Now, when transistor S is turned on for a predetermined period of time to establish a predetermined current in coil L, which is approximately determined by DC voltage VCC and resistor R1, and transistor S1 is turned off, the potential at point P will be as shown in Figure 3 (1). , a damped oscillation waveform oscillates above and below the potential vCC. The comparison circuit output 3a obtained by comparing this P point potential and the reference voltage VF via the comparison circuit 3 is as shown in FIG. 3(2). In Fig. 3 (1) and (2), the waveforms on the left side indicate the case where there is no metal, that is, there is no detected metal approaching the coil L, and the waveforms on the right side indicate the case where there is metal, that is, the case where the detected metal does not approach the coil L. Indicates a case where there is close contact with metal. In this way, the attenuation of the resonant waveform becomes faster (stronger) as the metal to be detected approaches. This is because an overcurrent flows in the metal to be detected close to the coil due to a change in the magnetic flux generated by the coil L. When the pulse output as the comparison circuit output 3a is counted by the counter 11 in this manner, the counted value becomes smaller when the metal to be detected approaches than when it does not approach. Therefore, conventionally, the count output (number of pulses) A of the counter 11 is set to one threshold value (
N), if the number of pulses A was N or more, it was determined that there was no metal, and if it was less than N, it was determined that there was metal.
しかしながら、従来の近接スイッチにおいては、カウン
タ11の計数値が固定の数値Nと比較されるため、共振
回路L,CのQなどのバラッキにより減衰波形がバラッ
キ、このため金属の有無が切換わる動作点が近接スイッ
チによりバラッキ、高精度の近接スイッチを実現するこ
とができなかった。
そこで本発明は、予め近接スイッチの調整時に、検出コ
イルの発生磁束内に被検出金属が無い時、または検出が
行われるべき所望の位置に被検出金属を置いた時のカウ
ンタの計数値をメモリに記憶させて置き、実際の近接ス
イッチとしての使用時に検出出力されたカウンタの計数
値をこのメモリに記憶された値から所定値を引いた値と
してのしきい値、または前記メモリの記憶値としてのし
きい値と比較して金属の有無を判別する近接スイッチの
判別装置を提供することにより前記の問題を解消するこ
とを課題とする。However, in conventional proximity switches, since the count value of the counter 11 is compared with a fixed value N, the attenuation waveform varies due to variations in the Q of the resonant circuits L and C, which causes an operation in which the presence or absence of metal is switched. The points varied due to the proximity switch, making it impossible to realize a high-precision proximity switch. Therefore, the present invention stores the count value of the counter when there is no metal to be detected within the magnetic flux generated by the detection coil or when the metal to be detected is placed at the desired position where detection is to be performed, when adjusting the proximity switch in advance. The count value of the counter detected and output when used as an actual proximity switch is set as a threshold value obtained by subtracting a predetermined value from the value stored in this memory, or as a value stored in the memory. An object of the present invention is to solve the above-mentioned problem by providing a discrimination device for a proximity switch that discriminates the presence or absence of metal by comparing it with a threshold value.
前記の課題を解決するために本発明の装置は、『自身が
作る磁束内に被検出金属が入り得るように配設されたコ
イル(Lなど)と、コンデンサ(Cなど)とを並列に接
続して共振回路を構成し、直流電源(VCCなど)を介
し(トランジスタSl,抵抗R1などを用いて)この共
振回路に所定の付勢を行ったのち前記直流電源をこの共
振回路から切離し、
二の切離しののち、前記コイルまたはコンデンサの電流
または電圧が所定のレベルまで減衰するまでの間に発生
する減衰共振波の波数を(比較回路3,カウンタ11な
どを介して求めたうえ、この波数を)所定の計数しきい
値と比較して、前記被検出金属の前記コイルへの近接の
有無を(パルス計数制御回路2などを介し)判別する近
接スイッチにおいて、
予め所定の状態(被検出金属がコイルLの発生磁束内に
無い状態、または該金属が検出されるべき所望の位置に
置かれた状態など)で、前記のように発生した減衰共振
波の波数を(書込手段13などを介し)格納され記憶す
る手段(メモリ15など)と、
この記憶値(Mなど)を用いて前記計数しきい値を(記
憶値Mから所定値αを差引いた値M一α、または記憶値
Mなどとして)設定する手段(書込手段14,計数値判
別手段12Aなど)と、を備えたもとする。In order to solve the above-mentioned problems, the device of the present invention “connects in parallel a coil (such as L) and a capacitor (such as C) arranged so that the metal to be detected can enter the magnetic flux it generates. to form a resonant circuit, and after applying a predetermined energization to this resonant circuit (using transistor Sl, resistor R1, etc.) via a DC power source (VCC, etc.), the DC power source is disconnected from this resonant circuit; After the disconnection of the coil or capacitor, the wave number of the attenuated resonant wave that occurs until the current or voltage of the coil or capacitor attenuates to a predetermined level is determined (via the comparator circuit 3, counter 11, etc.), and this wave number is calculated. ) In a proximity switch that determines (via pulse counting control circuit 2, etc.) whether or not the metal to be detected is in proximity to the coil by comparing with a predetermined counting threshold, The wave number of the damped resonant wave generated as described above is recorded (via the writing means 13, etc.) in a state where the metal is not within the magnetic flux generated by the coil L, or when the metal is placed at a desired position to be detected. ) and a means for storing and memorizing (such as the memory 15), and using this stored value (such as M), the counting threshold value (value M minus α obtained by subtracting a predetermined value α from the stored value M, or a stored value M, etc.). (as) setting means (writing means 14, count value determination means 12A, etc.).
実際に周囲に被検出金属が無い状態から計数値が所定値
以上小さく変化したときに金属有と判断するようにした
り、あるいは近接スイッチとして使用するときの計数値
を実際に被検出金属を検出されるべき位置に置いたとき
の計数値と比較して金属の近接の有無を判断するように
して、金属の高精度の近接検出を行わせる。It is possible to determine that metal is present when the count value changes smaller than a predetermined value from a state in which there is no metal to be detected in the surrounding area, or to change the count value when used as a proximity switch to the state where no metal is actually detected. Highly accurate proximity detection of metal is performed by comparing the count value when placed at the desired position to determine the presence or absence of metal proximity.
次に第1図を用いて本発明の実施例を説明する。
同図は本発明の一実施例としての構成を示す回路図で第
2図に対応するものである。第1図においては第2図に
対しパルス計数制御回路が新たな回ている。そしてさら
に回路2A外にメモリ15が付加されている。
次に第1図の動作を2つの実施例によって説明する。ま
ず第1の実施例としては、予めこの近接スイッチの調整
時に、検出コイルLの発生磁束内に被検出金属が無い状
態で比較回路3の出力パルス数38をカウンタ11で計
数し、その計数値Mを書込手段13を介してメモ1月5
に書込んで置くものである。
この場合、実際の近接スイッチとしての使用時において
は、読込手段14によりメモ1月5に書込まれた値Mが
計数値判別手段12Aにロードされ、この判別手段12
Aによって比較回路3の出力パルス数38を計数したカ
ウンタ11の値Aが、上記Mがら所定値αを差引いた値
として定・められたしきい値M−αと比較され、A≧M
−αのとき金属無、ARM一αのとき金属有と判定され
る。
また第2の実施例としては、同じくこの近接スイッチの
調整時に、被検出金属の近接が検出されるべき所望の位
置に被検出金属を置き、このときの比較回路3の出力パ
ルス数3aをカウンタl1で計数し、その計数値Mを書
込手段13を介してメモリ15に書き込んで置くもので
ある。この場合実際の近接スイッチとしての使用時にお
いては、読込手段14によりメモ1月5に書込まれた値
Mがしきい値として計数値判別手段12Aにロードされ
、この判別手段12Aによってこのしきい値Mと比較回
路3の出力パルス数3aを計数したカウンタ11の計数
値Aとが比較され、A≧Mのとき金属無、A〈Mのとき
金属有と判定される。Next, an embodiment of the present invention will be described using FIG. This figure is a circuit diagram showing a configuration as an embodiment of the present invention, and corresponds to FIG. 2. In FIG. 1, the pulse counting control circuit is rotated in a new manner compared to FIG. Furthermore, a memory 15 is added outside the circuit 2A. Next, the operation of FIG. 1 will be explained using two embodiments. In the first embodiment, when adjusting this proximity switch in advance, the number of output pulses 38 of the comparator circuit 3 is counted by the counter 11 in a state where there is no metal to be detected in the magnetic flux generated by the detection coil L, and the counted value is Memo January 5 via writing means 13
It should be written and placed in the . In this case, when actually used as a proximity switch, the reading means 14 loads the value M written in the memo 1/5 into the count value determining means 12A, and this determining means 12
The value A of the counter 11 that counts the number of output pulses 38 of the comparator circuit 3 by A is compared with a threshold value M-α determined as the value obtained by subtracting a predetermined value α from the above M, and A≧M.
It is determined that there is no metal when -α, and there is metal when ARM-α. Further, as a second embodiment, when adjusting the proximity switch, the metal to be detected is placed at a desired position where the proximity of the metal to be detected is to be detected, and the number of output pulses 3a of the comparison circuit 3 at this time is counted by a counter. 11, and the counted value M is written into the memory 15 via the writing means 13. In this case, when actually used as a proximity switch, the reading means 14 loads the value M written in the memo January 5 into the count value determining means 12A as a threshold value, and the determining means 12A The value M is compared with the count value A of the counter 11 that counts the number of output pulses 3a of the comparator circuit 3, and it is determined that there is no metal when A≧M, and that there is metal when A<M.
本発明によれば、予め近接スイッチの調整時、実際に検
出コイルの周囲に金属が無いときに出力されたカウンタ
計数値を記憶して置き、近接スイッチとして使用する際
は、検出された計数値が前記の記憶された計数値より所
定値以上小さくなったとき金属が有ると判定し、あるい
は
同じく近接スイッチの調整時、実際に金属の近接が検出
されるべき位置に被検出金属を置いた時に出力された計
数値を記憶して置き、近接スイッチとして使用する際は
検出された計数値と前記の記憶された計数値としてのし
きい値とを比較するようにしたため、共振回路L,Cの
バラツキばかりでなく、Rl,R2,R3のバラツキに
対しても有効な補正ができ、高精度の近接スイッチを得
ることができる。According to the present invention, when adjusting the proximity switch, the counter count value output when there is actually no metal around the detection coil is stored in advance, and when used as a proximity switch, the counter count value output when there is no metal around the detection coil is stored in advance. It is determined that metal is present when the value is smaller than the memorized count value by more than a predetermined value, or when the metal to be detected is placed at the position where the proximity of metal is actually detected when adjusting the proximity switch. The output count value is memorized and when used as a proximity switch, the detected count value is compared with the threshold value as the memorized count value, so that the resonant circuits L and C are It is possible to effectively correct not only the variations but also the variations in Rl, R2, and R3, and a highly accurate proximity switch can be obtained.
第1図は本発明の一実施例としての構成を示す回路図、
第2図は第1図は対応する従来の回路図、第3図は第2
図の動作説明用の波形図である。Fig. 1 is a circuit diagram showing a configuration as an embodiment of the present invention, Fig. 2 is a corresponding conventional circuit diagram, and Fig. 3 is a circuit diagram of a corresponding conventional circuit.
FIG. 3 is a waveform diagram for explaining the operation of the figure.
Claims (1)
設されたコイルと、コンデンサとを並列に接続して共振
回路を構成し、 直流電源を介しこの共振回路に所定の付勢を行ったのち
前記直流電源をこの共振回路から切離し、この切離しの
のち、前記コイルまたはコンデンサの電流または電圧が
所定のレベルまで減衰するまでの間に発生する減衰共振
波の波数を所定の計数しきい値と比較して、前記被検出
金属の前記コイルへの近接の有無を判別する近接スイッ
チにおいて、 予め所定の状態で前記のように発生した減衰共振波の波
数を格納され記憶する手段と、 この記憶値を用いて前記計数しきい値を設定する手段と
、 を備えたことを特徴とする近接スイッチの判別装置。[Claims] 1) A coil arranged so that the metal to be detected can enter the magnetic flux it generates and a capacitor are connected in parallel to form a resonant circuit, and this resonant circuit is connected via a DC power source. The wave number of the attenuated resonant wave that occurs after the DC power source is disconnected from the resonant circuit after a predetermined energization is applied to the coil or capacitor until the current or voltage in the coil or capacitor attenuates to a predetermined level. In the proximity switch, which compares the number of signals with a predetermined counting threshold to determine whether or not the metal to be detected is in proximity to the coil, the wave number of the damped resonant wave generated as described above in a predetermined state is stored in advance. A proximity switch discriminating device comprising: means for storing; and means for setting the counting threshold using the stored value.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1116815A JP2536148B2 (en) | 1989-05-10 | 1989-05-10 | Proximity switch identification device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1116815A JP2536148B2 (en) | 1989-05-10 | 1989-05-10 | Proximity switch identification device |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH02295222A true JPH02295222A (en) | 1990-12-06 |
JP2536148B2 JP2536148B2 (en) | 1996-09-18 |
Family
ID=14696329
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1116815A Expired - Lifetime JP2536148B2 (en) | 1989-05-10 | 1989-05-10 | Proximity switch identification device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2536148B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2007026799A1 (en) * | 2005-09-02 | 2007-03-08 | Azuma Systems Co., Ltd. | Proximity sensor and proximity detection method |
-
1989
- 1989-05-10 JP JP1116815A patent/JP2536148B2/en not_active Expired - Lifetime
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2007026799A1 (en) * | 2005-09-02 | 2007-03-08 | Azuma Systems Co., Ltd. | Proximity sensor and proximity detection method |
Also Published As
Publication number | Publication date |
---|---|
JP2536148B2 (en) | 1996-09-18 |
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